SIP Trunking & Peering Operation Guide

Transcription

1 SIP Trunking & Peering Operation Guide For Samsung OfficeServ May 07, 2008 doc v2.1.0 Sungwoo Lee Senior Engineer OfficeServ Network Lab. Telecommunication Systems Division Samsung Electronics Co., Ltd. 1

2 Contents 1. Introduction Overview SIP (Session Initiation Protocol) SIP Trunking vs. SIP Peering Locating SIP Server SIP Trunking Functionalities SIP Peering Functionalities Locating SIP Peer Multiple SIP Carriers SIP Station License Key Policy Overall Configuration Registration Registration Flow Authentication and Authorization Registration Types Trunk Registration Residential Registration SIP Trunking without Registration DNS Query Registration Example OfficeServ MMC Settings Message Samples SIP Trunking Services Basic Call Setup Basic Call MMC Settings Message Samples Hold & Resume Another way of specifying sendonly mode Transfer Consultation Transfer Blind Transfer

3 3.4. Call Forward Call Forward by a SIP Server Call Forward by OfficeServ Sending 302 Response Forwarding Received INVITE Alphanumeric Username Registering Alphanumeric Username Outgoing Alphanumeric Username Incoming Alphanumeric Username Multiple Alphanumeric Usernames SIP Trunking Related MMC837 Options Proxy Name field Session TMR SIP Peering Services Basic Call Setup

4 Figures Figure 1. SIP Call Scenario...6 Figure 2. Overall Configuration for SIP Trunking mode and SIP Station mode...10 Figure 3. Register Flow...11 Figure 4. Capture of DNS Query By OfficeServ...13 Figure 5. Basic Call Setup...16 Figure 6. Hold and Resume...22 Figure 7. Consultation Transfer # Figure 8. Consultation Transfer # Figure 9. Blind Transfer # Figure 10. Blind Transfer # Figure Moved Temporarily Received...45 Figure Moved Temporarily Sent...50 Figure 13. Forwarding Received INVITE...56 Figure 14. Register using Alphanumeric Username...65 Figure 15. Basic Outbound Call using Alphanumeric Username...68 Figure 16. Basic Inbound Call using Alphanumeric Username...75 Figure 17. Session Refreshed by OfficeServ...84 Figure 18. Overall Configuration for SIP Peering mode and SIP Station mode

5 Tables Table 1. SIP Trunking vs. SIP Peering...7 Table 2. SIP functionality comparison...7 Table 3. SIP Services Compatibility Table...9 5

6 1. Introduction 1.1. Overview This document is written in order to give guidelines to anybody involved with the SIP (Session Initiation Protocol) functions on OfficeServ systems made by Samsung Electronics. Readers of this document are assumed to have the minimum knowledge in operating OfficeServ systems for example, basic MMC settings, OfficeServ system configuration etc. By using this document, readers can become acquainted with a basic knowledge of SIP, and be able to configure the OfficeServ s SIP trunking and peering functions. As this document is mainly focusing on the SIP functionality on the OfficeServ system, readers who want to have in-depth understanding of SIP in general, should refer to RFC SIP (Session Initiation Protocol) SIP is an application-layer control protocol that can establish, modify, and terminate multimedia sessions (conferences) such as Internet telephony calls. SIP can also invite participants into already existing sessions, such as multicast conferences. Media can be added to (and removed from) an existing session. Standard SIP consists of mainly following 4 elements; User Agent Client (UAC): A user agent client is a logical entity that creates a new request. The role of UAC lasts only for the duration of that transaction. In other words, if a piece of software initiates a request, it acts as a UAC for the duration of that transaction. If it receives a request later, it assumes the role of a user agent server (UAS) for the processing of that transaction. Figure 1. SIP Call Scenario User Agent Server (UAS): A user agent server is a logical entity that generates a response to a SIP request. The response accepts, rejects, or redirects the request. This role lasts only for the duration of that transaction. In other words, if a piece of software responds to a request, it acts as a UAS for the duration of that transaction. If it generates a request later, it assumes the role of a user agent client for the processing of that transaction. Registrar: A registrar is a server that accepts REGISTER requests from UAC and places the information for location services. 6

7 SIP Server (or Proxy Server): A server is a network element that receives requests in order to service them and sends back responses to those requests. Examples of servers are proxies, user agent servers, redirect servers, and registrars SIP Trunking vs. SIP Peering OfficeServ system supports both SIP trunking and SIP peering. The main difference is whether to use a SIP server or not. If SIP messages are transmitted via an intermediary SIP server, we call this type of SIP connection, SIP trunking. Meanwhile, if SIP messages are directly transmitted between two end SIP UAs, it is SIP peering. Table 1. SIP Trunking vs. SIP Peering SIP Trunking SIP Peering SIP Server Use Use No Use Authentication REGISTER OPTIONS Message Outbound SIP Server Peer DNS Use No Use Related MMC No. 832, , Locating SIP Server In SIP trunking mode, OfficeServ can locate an outbound SIP server either by using DNS query or direct IP designation. If a direct IP is designated, OfficeServ sets the address as an outbound SIP Server s IP address. Instead, when an outbound proxy server s domain name is provided with DNS server s IP address, OfficeServ automatically triggers DNS query and fetches the IP addresses of the corresponding domain name from DNS servers. Once outbound server is set, all the SIP outbound messages from OfficeServ will send to the server. For some SIP carriers that require separate registrar server from outbound SIP server, OfficeServ is able to locate separate registrar server and its mechanism is the same with the case of locating SIP server. If separate registrar is set, OfficeServ sends out all the REGISTER messages to the registrar. Note that other SIP messages are still sent to the outbound server. DNS query feature is provided in OfficeServ 7100 and 7400 systems but not in OfficeServ 7200 and lower system SIP Trunking Functionalities SIP trunking functionality on the OfficeServ has two categories: Basic and Supplementary. Table 2. SIP functionality comparison Registration Basic Call Setup Basic Functions Supplementary Functions Hold/Resume Music on Hold Consultation Call Transfer (Consultation/Blind) Call Forward (All/Busy/No-Answer) DND 7

8 MWI Conference Call Waiting Call Pickup Call Park Basic SIP trunking functions in the OfficeServ have been implemented based on SIP standard, and they have been tested with various SIP carriers whose SIP servers were manufactured by many different 3 rd party vendors. OfficeServ s SIP supplementary service functions, however, were developed and tested mainly using BroadSoft Inc s Soft Switch (a SIP server), and thus there may be some compatibility problems when interoperating with other SIP servers made by different vendors. Another reason why we can not guarantee compatibility of supplementary functions is that each different SIP UA manufacturer can have each different SIP message handling scheme which does not matches with schemes implemented in OfficeServ system. For this reason, some features that are working fine with a certain SIP server may not work properly when interoperating with other servers SIP Peering Functionalities Unlike SIP trunking which normally depends on SIP server s capability, SIP peering functionalities are mostly depending on each participating SIP UA s capability. In many cases, therefore, supplementary features in SIP peering session are comparatively limited due to different SIP specification implemented in each different SIP UA Locating SIP Peer In SIP peering mode, SIP peer s location should be known to OfficeServ in order to send out its SIP messages by setting IP address of the peer Multiple SIP Carriers Currently OfficeServ system can interacts with only one SIP carrier at a time, but it has database frame which is able to contain 1 maximum 4 SIP carrier profile data in its MMC837. Each profile database designates each different SIP carrier and by setting the SIP SERVER field of a certain profile to ENABLE OfficeServ sets the corresponding SIP carrier as its default SIP carrier. Remember that only one SIP carrier can be active at a certain time. As mentioned, MMC837 contains 4 ISP (Internet Service Provider) database profiles as well as SIP and EXT databases. SIP menu specifies all commonly used parameters such as T1 and T2 timers SIP Station OfficeServ systems support not only SIP trunking/peering features but also SIP station features. 1 In later version, OfficeServ will be able to support multiple active SIP carriers at a time, which means it can decide which SIP carrier s outbound server to send SIP message to without manually changing a default active SIP carrier to another. 8

9 Any standard SIP phone can register to OfficeServ as its station and can be used to provide various supplement call features using SIP. We have tried to adapt the standard SIP call flow and message formats that IETF recommended when implementing SIP station features in order to make the services SIP station independent. But still, as in the case of SIP trunking/peering, because each different manufacturer may have each different call flow or message format, interoperability between OfficeServ and 3 rd party vendor products can be an issue in some cases. Currently OfficeServ system guarantees the supplementary SIP service features only for the following SIP terminals, which have been actually gone through rigorous SEC s lab-testing and adapted by OfficeServ. Table 3. SIP Services Compatibility Table For more detailed information on OfficeServ s SIP station, please refer to SIP Station Operation Guide License Key Policy If S/W version of MP (or MCP) in OfficeServ is 4.10 or higher, SIP license key should be set onto the OfficeServ system in order to use SIP features. SIP license key contains the information of SIP channel capabilities such as the number SIP trunk channels or the number SIP station channels. If there were not for a valid license key, OfficeServ can not send or receive any SIP call. License keys are issued only by a license server that is managed by license server manager. To obtain a valid license key, OfficeServ operator should consult the license key manager and let him know the MAC address of the corresponding OfficeServ system s MCP card. That means that use 9

10 of the license key issued for a specific MCP card is restricted only for the card, and can not be used for any other MCP card which has a different MAC address. As the number of SIP channels is set when creating the license key, you should let the license key manager know the desired number of SIP channels in advance along with the MP s MAC address Overall Configuration As shown in Figure 1, the SIP interfaces (remarked as dashed lines in each circle) in each OfficeServ domain are for SIP Station Mode, and external SIP interfaces that are connected to external SIP Servers are for SIP Trunk Mode. SIP Server 1 SIP Server 2 Internet OfficeServ 1 OfficeServ 2 Figure 2. Overall Configuration for SIP Trunking mode and SIP Station mode 10

11 2. Registration From SIP server s perspective, registration process has two meanings. One is to authenticate interacting SIP UAs, and the other is to locating SIP UAs. Though detailed registration processes may vary server to server, every server has to have those two mechanisms to provide VoIP services. SIP registration can be compared to registering an address. Let s take an example of sending and receiving an through an server. When you want to send an to your friend, you and your friend should have an address by which you can send and receive an . As an address needs to be registered to an server, a SIP UAC has to be registered to SIP registrar. Therefore, registering a SIP UAC to a SIP registrar is like registering an address to an server. As in the case of an address, a registered UAC has its own URI typed address called AOR or Address of Record. (i.e., [email protected]) Unlike an address, SIP UAC registration always comes with IP address to which SIP server can route SIP messages. This IP address is specified in the Contact header in a SIP register message. In addition, each SIP registration has an expiration period for which its registration can be held valid. OfficeServ users can configure this expire time and it is set to 3600 seconds by default. Finding a target UAC is done by the co-working of a SIP Proxy Server and Registrar. Once a SIP proxy has received a message from the sending UAC, it will consult a SIP registrar to discover the location of the target UAC. However, in many cases, the SIP proxy server and SIP registrar are implemented in a single SIP server. Therefore, in this document, we simply use a single term named SIP Server to designate a server that has both registrar functions and proxy functions Registration Flow A standard SIP registration procedure consists of Authentication and Authorization. Authentication is a UAC s request to a SIP server for its identity verification, and authorization is a SIP server s confirmation on the authentication. Authentication and authorization are handled on a request-by-request basis with a challenge/response mechanism between UAC and SIP server. Figure 3. Register Flow 11

12 As shown in above call flow, SIP registration process goes through 4 steps. i. UAC sends a Register message without authentication information. ii. iii. iv. SIP server gives back 407 response having authorization information. Upon receiving a 407 response, UAC creates a Register message again which contains valid authentication information. SIP server authorizes UAC s registration after confirming the authentication contained in the Register message Authentication and Authorization Authentication and authorization are, in brief, about creating encryption value and confirming the value between UAC and SIP server. This encryption value can be made from the composition of a username, password and nonce value. While UAC and SIP server publicly share the pair of username and password, a nonce value is created only by SIP server side using internal nonce value generating algorithm, and can be known to UAC when a 401 response message is transmitted from SIP server. After receiving a 401 response message, the UAC creates an encryption value, using username, password and nonce as encryption seeds, and assign it as a response parameter in the authorization header in the subsequent REGISTER message. If this response parameter value matches with an encryption value created by the SIP server, the SIP server finally authorizes the UAC s registration. As both SIP server and UAC have the same encryption seed of username, password, and nonce, the encryption value contained in the authorization header should be identical to encryption value made by SIP server. Among many authentication mechanisms for creating and confirming the encryption values, one of the most widely used is 2 MD5 digest algorithm. This algorithm originated from HTTP s web authentication, which is normally used in logon processes of many web sites. The detailed explanation for the MD5 digest algorithm is beyond the scope of this document. Although authentication and authorization are generally carried on the normal registration flow in SIP, it is not always the case. That is, some SIP Servers may not require UAC s authentication and instead, they may have simpler ways of filtering out invalid registration messages. For example, they may check caller number; SIP Servers allow registrations with designated caller number only. Another example is that SIP Servers check the domain name field in the contact header in registration messages. More often than not, however, SIP Servers follow the recommended standard way of authentication and authorization procedure for security reasons Registration Types There are two types of Registration. One is Trunk Registration and the other is Residential Registration. The former is much more widely used in industry and thus when we refer Registration, it means Trunk Registration. OfficeServ system supports both of these registration types and which to use is set using REG PER USER option entry in MMC837 in OfficeServ 2 By default, the OfficeServ system uses MD5 digest algorithm. In a 3GPP compatible environment, however, the OfficeServ system switches to AKA algorithm for authentication if 401 response from the SIP server requires the use of AKA authentication. Which algorithm to use is decided by SIP server 12

13 system; Disable means Trunk Registration and Enable means Residential Registration Trunk Registration Trunk Registration means that the OfficeServ system does a single registration, whose credential data is shared by all the SIP connections between OfficeServ and an outbound SIP server Residential Registration Residential Registration lets each individual user terminal attached to the OfficeServ have its own registration to a SIP server. This does not mean that each user terminal creates a registration message and directly sends it to the SIP server because many terminals other than Standard SIP terminals can not make SIP register messages. So, the OfficeServ creates each SIP message using pre-assigned registration information, and does the SIP registration process on behalf of each end terminal SIP Trunking without Registration Some SIP Servers do not require UA s registration at all. This type of server authenticates its interacting SIP UAs with their IP addresses and assigned usernames. That is, before starting interoperating with UA, SIP server administrator normally asks SIP UA s IP address and assigns predefined username, and stores the data somewhere in the server. This way, when any SIP message comes from the corresponding SIP UA, the SIP server checks the couple of source IP address and username and when matches with the data pre-stored in the server, it passes and rejects it otherwise. Sending REGISTER message to a SIP server that does not require registration is meaningless and rather worsening network traffic, and thus it is always better not to send useless REGISTER message. When leave USER NAME field in MMC837 blank, OfficeServ does not send REGISTER message though SIP SERVER is enabled DNS Query Figure 4. Capture of DNS Query By OfficeServ 13

14 OfficeServ is able to determine the location of the outbound SIP Server (registrar or proxy) based on the resolution of SRV and A queries. OfficeServ utilizes DNS servers specified in DNS SERVER1 & DNS SERVER2 fields to resolve SIP server names. Above ethereal capture shows the example of how DNS query for a registrar or an outbound server is made using FQDN of samsung.com from OfficeServ to a DNS server, and 3 IP addresses are fetched; , , and Registration Example OfficeServ MMC Settings MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com DNS SERVER1: USER NAME: AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE TRK REG EXP: Message Samples Reg F1 REGISTER sip:samsung.com:5060 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1dd38a8-8442d5a5-13c d3d- 180f5e d3d To: <sip: @samsung.com:5060> Call-ID: 1dd907c-8442d5a5-13c d3d-3488e d3d CSeq: 1 REGISTER Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48111d3d-82da38e6-4839db7a Max-Forwards: 70 Supported: 100rel,replaces Expires: 1800 Contact: <sip: @ :5060> Reg F2 SIP/ Proxy Authentication Required To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1dd38a8-8442d5a5-13c d3d- 180f5e d3d Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48111d3d-82da38e6-4839db7a CSeq: 1 REGISTER Call-ID: 1dd907c-8442d5a5-13c d3d-3488e d3d Proxy-Authenticate: Digest realm=" ",qop="auth",algorithm="md5",nonce="673d70c8cc cf3aa94277c3df" 14

15 Reg F3 REGISTER sip:samsung.com:5060 SIP/2.0 From: 180f5e d3d To: Call-ID: 1dd907c-8442d5a5-13c d3d-3488e d3d CSeq: 2 REGISTER Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48111d3d-82da cae6b8 Max-Forwards: 70 Supported: 100rel,replaces Expires: 1800 Proxy-Authorization: Digest username=" ",realm=" ",nonce="673d70c8cc cf3aa94277c3df ",uri="sip:samsung.com:5060",response="5df531fe6bc866c b4c1fa2ed",algorithm=md5,cnonce="82da3922",qop=auth,nc= \r Contact: <sip: @ :5060> Reg F4 SIP/ OK To: <sip: @samsung.com:5060>;tag=10322 From: <sip: @samsung.com:5060>;tag=1dd38a8-8442d5a5-13c d3d- 180f5e d3d Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48111d3d-82da cae6b8 CSeq: 2 REGISTER Call-ID: 1dd907c-8442d5a5-13c d3d-3488e d3d Contact: <sip: @ :5060>;expires=300 15

16 3. SIP Trunking Services This Chapter describes the detailed call scenarios involving the SIP service features in OfficeServ 7000 series system. There can be many different scenarios for each service depending on service types and thus, this document does not fully cover all the possible cases but some representative ones are listed for each category. As mentioned in section 1.3 SIP trunking vs. SIP peering, OfficeServ MUST check its registration status first to start SIP trunking services except for the case that outbound SIP server does not require registration process. How to check the registration status is described in chapter 2 Registration Basic Call Setup Following call flow shows a typical SIP outbound trunk messages transmitted between OfficeServ system and a SIP server. Figure 5. Basic Call Setup 16

17 Basic Call MMC Settings MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com DNS SERVER1: USER NAME: AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE TRK REG EXP: Above MMC 837 settings are the same with the settings used in registration. Therefore, if you already completed registration, simply skip this. MMC832 VOIP OUT DGT (O:00) ACCESS DGT: 82 (target destination prefix number) INSERT DGT: DGT LENGTH: 2 IP TABLE: 1 IP START: 0 SERVER USE: YES URI TYPE: SIP MMC832 table is used to decide the outbound destination of SIP messages from OfficeServ system. In the previous version of MP S/W, as long as SIP SERVER field in MMC837 is ENABLE and registration is complete, OfficeServ sent all the SIP message to the outbound proxy server. But from v4.21, OfficeServ checks MMC832 table as well in order to decide the outbound address. Only when SERVER USE field is set to YES, OfficeServ sends the SIP message to the outbound server. Otherwise it sends to a designated IP address specified in MMC833 which is used in SIP peering mode. We discuss the usage of MMC833 in more detail in chapter 4 SIP Peering Services. In the above example, ACCESS DGT specifies the digit 82 and DGT LENGTH is 2. This setting filters out any outbound called number that starts with 82. i.e., MMC323 SEND CLIP NO [201] SEND CLIP 1: (same username used for registration) MMC323 table designates the mapping from an internal line number to a registered SIP username (caller ID). MMC714 DID DIGIT DID DIGIT (xxx) DGT: (same username used for registration) 1:

18 MMC714 table designates the mapping from registered SIP username (called ID) to an internal line number Message Samples Inv F1 INVITE SIP/2.0 From: To: Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 1 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48112aa8-830ea0fe-491d7077 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Inv F2 SIP/ Proxy Authentication Required To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1da7d d5a5-13c aa8-33cf5a aa8 Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48112aa8-830ea0fe- 491d7077 CSeq: 1 INVITE Call-ID: 1dad d5a5-13c aa b-48112aa8 Proxy-Authenticate: Digest realm=" ",qop="auth",algorithm="md5",nonce=" e99bde1e948ee5e5a6a82 45e3" 18

19 Inv F3 ACK SIP/2.0 From: To: Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 1 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48112aa8-830ea0fe-491d7077 Max-Forwards: 70 Contact: <sip: @ :5060> Inv F4 INVITE sip: @samsung.com:5060 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da7d d5a5-13c aa8-33cf5a aa8 To: <sip: @samsung.com:5060> Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48112aa8-830ea130-13c28e0d Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce=" e99bde1e948ee5e5a6a8245e 3",uri="sip: @samsung.com:5060",response="20d0c e48b55c9e53c32b03c ",algorithm=md5,cnonce="830ea130",qop=auth,n Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Inv F5 SIP/ Trying To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1da7d d5a5-13c aa8-33cf5a aa8 Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48112aa8-830ea130-13c28e0d CSeq: 2 INVITE Call-ID: 1dad d5a5-13c aa b-48112aa8 Server: ININ-samsung-k1o0rnf

20 Inv F6 SIP/ Ringing Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48112aa8-830ea130-13c28e0d Contact: To: From: Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 2 INVITE User-Agent: X-Lite release 1011s stamp Inv F7 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48112aa8-830ea130-13c28e0d Contact: <sip: @ :23554;rinstance=09b0c09f1dd41754> To: <sip: @samsung.com:5060>;tag=5f2bc463 From: <sip: @samsung.com:5060>;tag=1da7d d5a5-13c aa8-33cf5a aa8 Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 2 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 0 2 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=sendrecv Inv F8 ACK sip: @ :23554;rinstance=09b0c09f1dd41754 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da7d d5a5-13c aa8-33cf5a aa8 To: <sip: @samsung.com:5060>;tag=5f2bc463 Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 2 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48112aab-830ead42-938cbd5 Max-Forwards: 70 Contact: <sip: @ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce=" e99bde1e948ee5e5a6a8245e 3",uri="sip: @samsung.com:5060",response="20d0c e48b55c9e53c32b03c ",algorithm=md5,cnonce="830ea130",qop=auth,n 20

21 Inv F9 BYE SIP/2.0 From: To: Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 3 BYE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-48112aba-830ee97e c3 Max-Forwards: 70 Supported: 100rel,replaces Proxy-Authorization: Digest username=" ",realm=" ",nonce=" e99bde1e948ee5e5a6a8245e 3",uri="sip: @ :23554;rinstance=09b0c09f1dd41754",response="832b2e6 abc cf103367",algorithm=md Inv F10 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-48112aba-830ee97e c3 Contact: <sip: @ :23554;rinstance=09b0c09f1dd41754> To: <sip: @samsung.com:5060>;tag=5f2bc463 From: <sip: @samsung.com:5060>;tag=1da7d d5a5-13c aa8-33cf5a aa8 Call-ID: 1dad d5a5-13c aa b-48112aa8 CSeq: 3 BYE User-Agent: X-Lite release 1011s stamp

22 3.2. Hold & Resume Hold and Resume are bases of all the other SIP supplementary services. As many SIP services consist of a combination of Hold and Resume functions, it is essential to understand the internal mechanism of them in order to understand the mechanisms of more complicated services. According to the SIP standard, the Hold/Resume service can be implemented by either an UPDATE method or Re-INVITE method. The basic mechanism that lies in both of the two methods is the same although messages have different names. Currently the OfficeServ supports Re-INVITE message as its default Hold/Resume method. The Re-INVITE is a normal INVITE message except it is sent within an active session. By sending an INVITE message which contains different 3 SDP (Session Description Protocol) during a session, the SIP session mode can be switched to one of sendrecv, sendonly and recvonly according to the session mode attribute value designated in the SDP. Figure 6. Hold and Resume 3 SDP specifies the session attributes such as codec types, RTP port, RTP IP address etc. For more detailed information, please refer to RFC

23 Hold F1 INVITE SIP/2.0 From: To: Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 3 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK c-137dbf65 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="e6d451a0e7558d ea5f24cd8 0",uri="sip: @ :23554;rinstance=9c39f4fb86603c5e",response="8e8cc fb57043ffec820dd2f7",algorithm=MD Content-Length: 198 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendonly Hold F2 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK c- 137dbf65 Contact: <sip: @ :23554;rinstance=9c39f4fb86603c5e> To: <sip: @samsung.com:5060>;tag=74757e1e From: <sip: @samsung.com:5060>;tag=1da8da0-8442d5a5-13c Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 3 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 4 3 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=recvonly 23

24 Hold F3 ACK SIP/2.0 From: To: Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 3 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK c74f0d Max-Forwards: 70 Contact: <sip: @ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="e6d451a0e7558d ea5f24cd8 0",uri="sip: @ :23554;rinstance=9c39f4fb86603c5e",response="8e8cc fb57043ffec820dd2f7",algorithm=MD Resume F4 INVITE sip: @ :23554;rinstance=9c39f4fb86603c5e SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da8da0-8442d5a5-13c To: <sip: @samsung.com:5060>;tag=74757e1e Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 4 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK a172-27f7807b Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="e6d451a0e7558d ea5f24cd8 0",uri="sip: @ :23554;rinstance=9c39f4fb86603c5e",response="096ab00 5bf073eb35c30e9b9a89f950d",algorithm=MD Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv 24

25 Hold F5 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK a172-27f7807b Contact: To: From: Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 4 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 4 4 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=sendrecv Hold F6 ACK sip: @ :23554;rinstance=9c39f4fb86603c5e SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da8da0-8442d5a5-13c To: <sip: @samsung.com:5060>;tag=74757e1e Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 4 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK a d40 Max-Forwards: 70 Contact: <sip: @ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="e6d451a0e7558d ea5f24cd8 0",uri="sip: @ :23554;rinstance=9c39f4fb86603c5e",response="096ab00 5bf073eb35c30e9b9a89f950d",algorithm=MD 25

26 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK c- 137dbf65 Contact: To: From: Call-ID: 1db8a d5a5-13c cd79b4d CSeq: 3 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 4 3 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=recvonly In a normal dialogue state, the active session mode is sendrecv which allows both way RTP transmissions. When a Re-INVITE message is sent which designates its RTP transmission to sendonly mode, it informs the called party that it wants to only send RTP and will not receive. After receiving the Re-Invite message, the called party knows that the caller wants to put the session into hold mode and stops sending RTP packets, giving a 200 OK response back. The 200 OK response, like the Re-Invite message, contains a SDP and its session mode attribute is set to recvonly. Meanwhile, the caller can either provide music-on-hold or mute the session by sending no RTP at all, shutting down its listening port. Whether to send MOH or not during the hold time is station dependent. To resume the held session, the caller sends a Re-INVITE message again designating the RTP transmission back to sendrecv. Remember that only the caller can resume the held session, which means that even if the called party sends a Re-INVITE message specifying sendrecv, the session will remain on hold and caller s mode will not change Another way of specifying sendonly mode Some SIP UAs use another, slightly older way of specifying the sendonly mode in its Re-INVITE message. It sets the connection parameter value in the SDP to all zeros, which tells the message receiver (the called party in this context) not to send any RTP packets because there is no destination IP address to which it can send RTP packets to. The OfficeServ supports this connection-allzero-specified hold method for backward compatibility purpose. 26

27 3.3. Transfer Consultation Transfer Figure 7. Consultation Transfer #1 27

28 Figure 8. Consultation Transfer #2 28

29 Cons_Xfer F1 INVITE SIP/2.0 From: To: Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf c8-761d0576 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 198 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendonly Cons_Xfer F2 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf c8-761d0576 Contact: <sip: @ :35925;rinstance=bbe52bb8ca87498e> To: <sip: @samsung.com:5060>;tag= f From: <sip: @samsung.com:5060>;tag=1da74a8-8442d5a5-13c cf15-53ca178a-4812cf15 Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 2 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 8 3 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=recvonly 29

30 Cons_Xfer F3 ACK SIP/2.0 From: To: Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 2 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf Max-Forwards: 70 Contact: <sip: @ :5060> Cons_Xfer F4 INVITE sip: @samsung.com:5060 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e To: <sip: @samsung.com:5060> Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 1 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Cons_Xfer F5 SIP/ Trying To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 CSeq: 1 INVITE Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Server: ININ-samsung-k1o0rnf

31 Cons_Xfer F6 INVITE SIP/2.0 From: 59ae96c3-4812cf2e To: Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 1 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk32d96b6ac39e1c59db0fbef76, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 Max-Forwards: 69 Supported: 100rel, replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Cons_Xfer F7 SIP/ Trying Via: SIP/2.0/UDP ;branch=z9hG4bk32d96b6ac39e1c59db0fbef76, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e To: <sip: @samsung.com:5060> Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Date: Tue, 29 Apr :19:13 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE 31

32 Cons_Xfer F8 SIP/ Ringing Via: SIP/2.0/UDP ;branch=z9hG4bk32d96b6ac39e1c59db0fbef76, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 From: 59ae96c3-4812cf2e To: Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Date: Tue, 29 Apr :19:13 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Cons_Xfer F9 SIP/ Ringing Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e To: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Date: Tue, 29 Apr :19:13 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE 32

33 Cons_Xfer F10 SIP/ OK Via: SIP/2.0/UDP ;branch=z9hG4bk32d96b6ac39e1c59db0fbef76, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 From: 59ae96c3-4812cf2e To: Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Date: Tue, 29 Apr :19:14 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv Cons_Xfer F11 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf2e-89794f0c-1ffada59 From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e To: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Date: Tue, 29 Apr :19:14 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv 33

34 Cons_Xfer F12 ACK SIP/2.0 From: 59ae96c3-4812cf2e To: Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 1 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf a8d91 Max-Forwards: 70 Contact: <sip: @ :5060> Cons_Xfer F13 INVITE sip: @ :5060;transport=udp SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e To: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf f6-46aa233f Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 198 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendonly 34

35 Cons_Xfer F14 SIP/ OK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf f6-46aa233f From: 59ae96c3-4812cf2e To: Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Date: Tue, 29 Apr :19:18 GMT CSeq: 2 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=inactive Cons_Xfer F15 ACK sip: @ :5060;transport=udp SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e To: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 2 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf d83433b Max-Forwards: 70 Contact: <sip: @ :5060> 35

36 Cons_Xfer F16 REFER SIP/2.0 From: To: Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 3 REFER Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf cb90d9b Refer-To: <sip: @samsung.com:5060?replaces=1dad d5a5-13c cf2e-22010d5-4812cf2e%3Bto-tag%3D00141ca537d c9b6e0-046b20b9%3Bfromtag%3D1da d5a5-13c cf2e-59ae96c3-4812cf2e> Referred-By: <sip: @samsung.com> Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Cons_Xfer F17 SIP/ Accepted Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf cb90d9b Contact: <sip: @ :35925;rinstance=bbe52bb8ca87498e> To: <sip: @samsung.com:5060>;tag= f From: <sip: @samsung.com:5060>;tag=1da74a8-8442d5a5-13c cf15-53ca178a-4812cf15 Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 3 REFER Expires: 60 User-Agent: X-Lite release 1011s stamp Cons_Xfer F18 NOTIFY sip: @ :5060 SIP/2.0 Via: SIP/2.0/UDP :35925;branch=z9hG4bK-d ef ed2e-1--d ;rport Max-Forwards: 70 Contact: <sip: @ :35925;rinstance=bbe52bb8ca87498e> To: <sip: @samsung.com:5060>;tag=1da74a8-8442d5a5-13c cf15-53ca178a-4812cf15 From: <sip: @samsung.com:5060>;tag= f Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 2 NOTIFY Content-Type: message/sipfrag User-Agent: X-Lite release 1011s stamp Subscription-State: active;expires=56 Event: refer Content-Length: 22 36

37 Cons_Xfer F19 INVITE SIP/2.0 Via: SIP/2.0/UDP :35925;branch=z9hG4bK-d a501a2a61d d ;rport Max-Forwards: 70 Contact: To: From: Call-ID: YThiZjIzYTlmOTdkM2RkZTc3ZDdkNjhmYWI3ZDJlN2E. CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Referred-By: <sip: @samsung.com> Replaces: 1dad d5a5-13c cf2e-22010d5-4812cf2e;to- tag=00141ca537d c9b6e0-046b20b9;from-tag=1da d5a5-13c cf2e-59ae96c3-4812cf2e Content-Length: 423 o=- 4 2 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=alt:1 1 : 4nKLQGQu qvgev a=fmtp: a=rtpmap:107 BV32/16000 a=rtpmap:119 BV32-FEC/16000 a=rtpmap:100 SPEEX/16000 a=rtpmap:106 SPEEX-FEC/16000 a=rtpmap:105 SPEEX-FEC/8000 a=rtpmap:98 ilbc/8000 a=sendrecv Cons_Xfer F20 SIP/ Trying To: <sip: @samsung.com:5060> From: " " <sip: @samsung.com>;tag=4c6c4a7f Via: SIP/2.0/UDP :35925;branch=z9hG4bK-d a501a2a61d d ;rport=35925 CSeq: 1 INVITE Call-ID: YThiZjIzYTlmOTdkM2RkZTc3ZDdkNjhmYWI3ZDJlN2E. Server: ININ-samsung-k1o0rnf

38 Cons_Xfer F21 INVITE SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bk0d899cacc eed90b4c, SIP/2.0/UDP :35925;rport=35925;branch=z9hG4bK-d a501a2a61d d Max-Forwards: 69 Contact: To: From: " " Call-ID: YThiZjIzYTlmOTdkM2RkZTc3ZDdkNjhmYWI3ZDJlN2E. CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Referred-By: <sip: @samsung.com> Replaces: 1dad d5a5-13c cf2e-22010d5-4812cf2e;to- tag=00141ca537d c9b6e0-046b20b9;from-tag=1da d5a5-13c cf2e-59ae96c3-4812cf2e Content-Length: 423 o=- 4 2 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=alt:1 1 : 4nKLQGQu qvgev a=fmtp: a=rtpmap:107 BV32/16000 a=rtpmap:119 BV32-FEC/16000 a=rtpmap:100 SPEEX/16000 a=rtpmap:106 SPEEX-FEC/16000 a=rtpmap:105 SPEEX-FEC/8000 a=rtpmap:98 ilbc/8000 a=sendrecv Cons_Xfer F22 SIP/ OK From: <sip: @samsung.com:5060>;tag= f To: <sip: @samsung.com:5060>;tag=1da74a8-8442d5a5-13c cf15-53ca178a-4812cf15 Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 2 NOTIFY Via: SIP/2.0/UDP :35925;rport=35925;branch=z9hG4bK-d ef ed2e- 1--d Supported: 100rel,replaces Contact: <sip: @ :5060> 38

39 Cons_Xfer F23 SIP/ Trying Via: SIP/2.0/UDP ;branch=z9hG4bk0d899cacc eed90b4c, SIP/2.0/UDP :35925;rport=35925;branch=z9hG4bK-d a501a2a61d d From: " " To: Call-ID: YThiZjIzYTlmOTdkM2RkZTc3ZDdkNjhmYWI3ZDJlN2E. Date: Tue, 29 Apr :19:22 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Cons_Xfer F24 SIP/ OK Via: SIP/2.0/UDP ;branch=z9hG4bk0d899cacc eed90b4c, SIP/2.0/UDP :35925;rport=35925;branch=z9hG4bK-d a501a2a61d d From: " " <sip: @samsung.com>;tag=4c6c4a7f To: <sip: @samsung.com:5060>;tag=00141ca537d400580fa5f f11 Call-ID: YThiZjIzYTlmOTdkM2RkZTc3ZDdkNjhmYWI3ZDJlN2E. Date: Tue, 29 Apr :19:23 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 206 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=fmtp: a=sendrecv 39

40 Cons_Xfer F25 SIP/ OK Via: SIP/2.0/UDP :35925;rport=35925;branch=z9hG4bK-d a501a2a61d d From: " " To: Call-ID: YThiZjIzYTlmOTdkM2RkZTc3ZDdkNjhmYWI3ZDJlN2E. Date: Tue, 29 Apr :19:23 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 206 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=fmtp: a=sendrecv Cons_Xfer F26 NOTIFY sip: @ :5060 SIP/2.0 Via: SIP/2.0/UDP :35925;branch=z9hG4bK-d f3df71c d ;rport Max-Forwards: 70 Contact: <sip: @ :35925;rinstance=bbe52bb8ca87498e> To: <sip: @samsung.com:5060>;tag=1da74a8-8442d5a5-13c cf15-53ca178a-4812cf15 From: <sip: @samsung.com:5060>;tag= f Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 3 NOTIFY Content-Type: message/sipfrag User-Agent: X-Lite release 1011s stamp Subscription-State: terminated;reason=noresource Event: refer Content-Length: 18 40

41 Cons_Xfer F27 SIP/ OK From: To: Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 3 NOTIFY Via: SIP/2.0/UDP :35925;rport=35925;branch=z9hG4bK-d f3df71c d Supported: 100rel,replaces Contact: <sip: @ :5060> Cons_Xfer F28 BYE sip: @ :5060 SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK77330deb From: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 To: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Max-Forwards: 70 Date: Tue, 29 Apr :19:23 GMT CSeq: 101 BYE User-Agent: Cisco-CP7960G/8.0 Cons_Xfer F29 BYE sip: @ :5060 SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bkad2bb3d29dd c3f6, SIP/2.0/UDP :5060;branch=z9hG4bK77330deb From: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 To: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e Max-Forwards: 69 Date: Tue, 29 Apr :19:23 GMT CSeq: 101 BYE User-Agent: Cisco-CP7960G/8.0 Cons_Xfer F30 SIP/ OK From: <sip: @samsung.com:5060>;tag=00141ca537d c9b6e0-046b20b9 To: <sip: @samsung.com:5060>;tag=1da d5a5-13c cf2e- 59ae96c3-4812cf2e Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 101 BYE Via: SIP/2.0/UDP ;branch=z9hG4bkad2bb3d29dd c3f6 Via: SIP/2.0/UDP :5060;branch=z9hG4bK77330deb Supported: 100rel,replaces 41

42 Cons_Xfer F31 SIP/ OK From: To: 59ae96c3-4812cf2e Call-ID: 1dad d5a5-13c cf2e-22010d5-4812cf2e CSeq: 101 BYE Via: SIP/2.0/UDP :5060;branch=z9hG4bK77330deb Supported: 100rel, replaces Cons_Xfer F32 BYE SIP/2.0 From: To: Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 4 BYE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4812cf f6133 Max-Forwards: 70 Supported: 100rel,replaces Cons_Xfer F33 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4812cf f6133 Contact: <sip: @ :35925;rinstance=bbe52bb8ca87498e> To: <sip: @samsung.com:5060>;tag= f From: <sip: @samsung.com:5060>;tag=1da74a8-8442d5a5-13c cf15-53ca178a-4812cf15 Call-ID: 1dad2a0-8442d5a5-13c cf15-5b4c6c cf15 CSeq: 4 BYE User-Agent: X-Lite release 1011s stamp

43 Blind Transfer Figure 9. Blind Transfer #1 43

44 Figure 10. Blind Transfer #2 44

45 3.4. Call Forward Call Forward feature is to redirect a call to an original recipient to the other recipient. According to who is redirector, OfficeServ should behave differently. When redirecting a call, the original recipient should respond with a 302 REDIRECTED response. Therefore, if OfficeServ is the one who redirects the call, it should answer with 302 REDIRECTED against received INVITE message and if it is the opposite case, OfficeServ will receive the 302 response. This chapter shows how OfficeServ reacts on these two different cases Call Forward by a SIP Server Call Forward feature is set on either a SIP server or a recipient. In whichever case, OfficeServ is supposed to receive a 302 response and should re-send the original INVITE message to the forwarded recipient. Figure Moved Temporarily Received 45

46 302_rcvd F1 INVITE SIP/2.0 From: 1988c5e6-4813d39b To: Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b CSeq: 1 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4813d39b-8d72971c-224f9640 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv 302_rcvd F2 SIP/ Trying To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1da8ab0-8442d5a5-13c d39b- 1988c5e6-4813d39b Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4813d39b-8d72971c- 224f9640 CSeq: 1 INVITE Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b Server: ININ-samsung-k1o0rnf

47 302_rcvd F3 INVITE SIP/2.0 From: 1988c5e6-4813d39b To: Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b CSeq: 1 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk3815f9ba38f7f9ac638fd3efa, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4813d39b-8d72971c-224f9640 Max-Forwards: 69 Supported: 100rel, replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv 302_rcvd F4 SIP/ Moved Temporarily Via: SIP/2.0/UDP ;branch=z9hG4bk3815f9ba38f7f9ac638fd3efa, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4813d39b-8d72971c-224f9640 From: <sip: @samsung.com:5060>;tag=1da8ab0-8442d5a5-13c d39b- 1988c5e6-4813d39b To: <sip: @samsung.com:5060>;tag=00141ca537d401f860ff e59e4 Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b Date: Wed, 30 Apr :50:42 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060> Diversion: " " <sip: @ >;reason=unconditional;privacy=off;screen=yes Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE 302_rcvd F5 ACK sip: @ :5060 SIP/2.0 To: <sip: @samsung.com:5060>;tag=00141ca537d401f860ff e59e4 From: <sip: @samsung.com:5060>;tag=1da8ab0-8442d5a5-13c d39b- 1988c5e6-4813d39b Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b Via: SIP/2.0/UDP ;branch=z9hG4bk3815f9ba38f7f9ac638fd3efa CSeq: 1 ACK 47

48 302_rcvd F6 SIP/ Moved Temporarily Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4813d39b-8d72971c- 224f9640 From: 1988c5e6-4813d39b To: Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b Date: Wed, 30 Apr :50:42 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060> Diversion: " " <sip: @ >;reason=unconditional;privacy=off;screen=yes Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE 302_rcvd F7 ACK sip: @samsung.com:5060 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da8ab0-8442d5a5-13c d39b- 1988c5e6-4813d39b To: <sip: @samsung.com:5060>;tag=00141ca537d401f860ff e59e4 Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b CSeq: 1 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4813d39b-8d72971c-224f9640 Max-Forwards: 70 Contact: <sip: @ :5060> 302_rcvd F8 INVITE sip: @ :5060 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1da8ab0-8442d5a5-13c d39b- 1988c5e6-4813d39b To: <sip: @samsung.com:5060> Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4813d39c-8d729bfe-218bc766 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv 48

49 302_rcvd F9 SIP/ Trying To: From: 1988c5e6-4813d39b Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4813d39c-8d729bfe- 218bc766 CSeq: 2 INVITE Call-ID: 1dadcf0-8442d5a5-13c d39b-f9a83c8-4813d39b Server: ININ-retail_ Call Forward by OfficeServ If OfficeServ is the one who sets the call forward, it can have two different options in doing it; either sending 302 Response back to the caller or forwarding the received INVITE to a designated destination. The former is that OfficeServ, as in the case of 3.4.1, asks the original caller to redirect the call to designated destination, and the latter is OfficeServ itself redirects the call by sending an INVITE to the 3 rd destination. This is how to set call forward in OfficeServ using MMC102. Let s assume that OfficeServ has been assigned a primary number of and when it receives an INVITE message, whose called number in TO header is the primary number, it sends the call to a station 201. MMC714 SEND CLIP NO DID DIGIT (xxx) DGT: (same username used for registration) 1: 201 MMC102 CALL FORWARD [201] FORWARD 1. FWD ALL: When a call is received to station 201, the call is forwarded to the designated number in FWD ALL field. In example, staring digit 805 is SIP trunk group number, and thus we can see that incoming call is to be forwarded to a number of using SIP trunk line Sending 302 Response MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com DNS SERVER1: USER NAME: AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE TRK REG EXP: RESP: ENABLE 49

50 Above MMC 837 settings are the same with the settings used in registration except for the last item. In order to respond with Moved Temporarily, OfficeServ needs to set 302 RESP field to ENABLE. Figure Moved Temporarily Sent 4 Note that sending a 302 Moved Temporarily response is possible only when set ALL CALL FORWARD. 50

51 302_send F1 INVITE SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc From: " " 3e To: Call-ID: Max-Forwards: 70 Date: Thu, 01 May :35:33 GMT CSeq: 101 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 278 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv 302_ send F2 SIP/ Trying To: <sip: @samsung.com> From: " " <sip: @samsung.com>;tag=00141ca537d4040a3e4a561a- 3e Via: SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc CSeq: 101 INVITE Call-ID: 00141ca5-37d d54-165be706@ Server: ININ-samsung-k1o0rnf

52 302_send F3 INVITE SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bk2d926da1868c1e3f , SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc From: " " 3e To: Call-ID: Max-Forwards: 69 Date: Thu, 01 May :35:33 GMT CSeq: 101 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 278 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv 302_ send F4 SIP/ Trying From: " "<sip: @samsung.com>;tag=00141ca537d4040a3e4a561a- 3e To: <sip: @samsung.com> Call-ID: 00141ca5-37d d54-165be706@ CSeq: 101 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk2d926da1868c1e3f Via: SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc Supported: 100rel,replaces Contact: <sip: @ :5060> 52

53 302_ send F5 SIP/ Moved Temporarily From: 3e To: Call-ID: CSeq: 101 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk2d926da1868c1e3f Via: SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc Supported: 100rel,replaces Contact: 302_ send F6 ACK SIP/2.0 To: From: " " 3e Call-ID: Via: SIP/2.0/UDP ;branch=z9hG4bk2d926da1868c1e3f CSeq: 101 ACK 302_ send F7 SIP/ Moved Temporarily From: " " 3e To: Call-ID: CSeq: 101 INVITE Via: SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc Supported: 100rel, replaces Contact: 302_ send F8 ACK SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK2e3be9dc From: " " 3e To: Call-ID: Date: Thu, 01 May :35:34 GMT CSeq: 101 ACK 53

54 302_send F9 INVITE SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK592e280d From: " " To: Call-ID: Max-Forwards: 70 Date: Thu, 01 May :35:34 GMT CSeq: 102 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 278 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv 302_ send F10 SIP/ Trying To: <sip: @samsung.com> From: " " <sip: @samsung.com>;tag=00141ca537d4040b3b27c831-24b59245 Via: SIP/2.0/UDP :5060;branch=z9hG4bK592e280d CSeq: 102 INVITE Call-ID: 00141ca5-37d d54-165be706@ Server: ININ-samsung-k1o0rnf

55 302_send F9 INVITE SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bk ebf9a4939e16ce8d16, SIP/2.0/UDP :5060;branch=z9hG4bK592e280d From: " " To: Call-ID: Max-Forwards: 69 Date: Thu, 01 May :35:34 GMT CSeq: 102 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 278 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv Forwarding Received INVITE Forwarding a received INVITE message to a designated number is another way of doing Call Forward. There is only one difference in MMC837 setting from the case of sending 302 response: setting 302 RESP to DISABLE. MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com DNS SERVER1: USER NAME: AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE TRK REG EXP: RESP: DISABLE As seen in sample messages, OfficeServ does not forward the received INVITE as it is, rather it 55

56 sends its own INVITE message to the designated destination. That is, in this way, one SIP session is made between the original caller and OfficeServ, and the second SIP session is additionally made between OfficeServ and the 3 rd destination. Each SIP session consumes each MGI resource in OfficeServ and the RTP packets should go through 4 steps of encoding and decoding procedure, which degrades voice quality significantly. Thus this INVITE message forwarding is not a good way to do call forward. Figure 13. Forwarding Received INVITE 56

57 Fwd_inv F1 INVITE SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 From: " " 5b2da26a To: Call-ID: Max-Forwards: 70 Date: Fri, 02 May :22:33 GMT CSeq: 101 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 278 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv Fwd_inv F2 SIP/ Trying To: <sip: @samsung.com> From: " " <sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 CSeq: 101 INVITE Call-ID: 00141ca5-37d a485c7-3a0c34e8@ Server: ININ-samsung-k1o0rnf

58 Fwd_inv F3 INVITE SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bk21691eeeb ff6422ac, SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 From: " " 5b2da26a To: Call-ID: Max-Forwards: 69 Date: Fri, 02 May :22:33 GMT CSeq: 101 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 278 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv Fwd_inv F4 SIP/ Trying From: " "<sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a To: <sip: @samsung.com> Call-ID: 00141ca5-37d a485c7-3a0c34e8@ CSeq: 101 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk21691eeeb ff6422ac Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 Supported: 100rel,replaces Contact: <sip: @ :5060> 58

59 Fwd_inv F5 INVITE SIP/2.0 From: To: Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4816c456-98eef ef18 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Fwd_inv F6 SIP/ Trying To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1dd d5a5-13c c456-41f71b1e-4816c456 Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c456-98eef ef18 CSeq: 1 INVITE Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 Server: ININ-samsung-k1o0rnf

60 Fwd_inv F7 INVITE SIP/2.0 From: To: Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk85d ac74bc804eecc, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c456-98eef ef18 Max-Forwards: 69 Supported: 100rel, replaces Contact: <sip: @ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Fwd_inv F8 SIP/ Ringing From: " "<sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a To: <sip: @samsung.com>;tag=1dd41d8-8442d5a5-13c c456-64e583c1-4816c456 Call-ID: 00141ca5-37d a485c7-3a0c34e8@ CSeq: 101 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk21691eeeb ff6422ac Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 Supported: 100rel,replaces Contact: <sip: @ :5060> Fwd_inv F9 SIP/ Ringing From: " " <sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a To: <sip: @samsung.com>;tag=1dd41d8-8442d5a5-13c c456-64e583c1-4816c456 Call-ID: 00141ca5-37d a485c7-3a0c34e8@ CSeq: 101 INVITE Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 Supported: 100rel, replaces Contact: <sip: @ :5060> 60

61 Fwd_inv F10 SIP/ OK From: 5b2da26a To: Call-ID: CSeq: 101 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk21691eeeb ff6422ac Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 Supported: 100rel,replaces Contact: Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv Fwd_inv F11 SIP/ OK From: " " <sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a To: <sip: @samsung.com>;tag=1dd41d8-8442d5a5-13c c456-64e583c1-4816c456 Call-ID: 00141ca5-37d a485c7-3a0c34e8@ CSeq: 101 INVITE Via: SIP/2.0/UDP :5060;branch=z9hG4bK378c08e1 Supported: 100rel, replaces Contact: <sip: @ :5060> Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv 61

62 Fwd_inv F12 SIP/ Ringing Via: SIP/2.0/UDP ;branch=z9hG4bk85d ac74bc804eecc Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c456-98eef ef18 Contact: To: From: Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 INVITE User-Agent: X-Lite release 1011s stamp Fwd_inv F13 SIP/ Ringing Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c456-98eef ef18 Contact: <sip: @ :9298;rinstance=aa040136f1a83a06> To: <sip: @samsung.com:5060>;tag=1e3cf677 From: <sip: @samsung.com:5060>;tag=1dd d5a5-13c c456-41f71b1e-4816c456 Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 INVITE User-Agent: X-Lite release 1011s stamp Fwd_inv F14 ACK sip: @ :5060 SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK4cd44590 From: " " <sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a To: <sip: @samsung.com>;tag=1dd41d8-8442d5a5-13c c456-64e583c1-4816c456 Call-ID: 00141ca5-37d a485c7-3a0c34e8@ Max-Forwards: 70 Date: Fri, 02 May :22:35 GMT CSeq: 101 ACK User-Agent: Cisco-CP7960G/8.0 Fwd_inv F15 ACK sip: @ :5060 SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bk5c55e719a63eb221e19a75945, SIP/2.0/UDP :5060;branch=z9hG4bK4cd44590 From: " " <sip: @samsung.com>;tag=00141ca537d a1c- 5b2da26a To: <sip: @samsung.com>;tag=1dd41d8-8442d5a5-13c c456-64e583c1-4816c456 Call-ID: 00141ca5-37d a485c7-3a0c34e8@ Max-Forwards: 69 Date: Fri, 02 May :22:35 GMT CSeq: 101 ACK User-Agent: Cisco-CP7960G/8.0 62

63 Fwd_inv F16 SIP/ OK Via: SIP/2.0/UDP ;branch=z9hG4bk85d ac74bc804eecc Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c456-98eef ef18 Contact: To: From: Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 5 2 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=sendrecv Fwd_inv F17 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c456-98eef ef18 Contact: <sip: @ :9298;rinstance=aa040136f1a83a06> To: <sip: @samsung.com:5060>;tag=1e3cf677 From: <sip: @samsung.com:5060>;tag=1dd d5a5-13c c456-41f71b1e-4816c456 Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 INVITE Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, NOTIFY, MESSAGE, SUBSCRIBE, INFO User-Agent: X-Lite release 1011s stamp Content-Length: 185 o=- 5 2 IN IP s=counterpath X-Lite 3.0 c=in IP m=audio RTP/AVP a=fmtp: a=sendrecv 63

64 Fwd_inv F18 ACK SIP/2.0 From: To: Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-4816c45e-98ef1264-4c05d5be Max-Forwards: 70 Contact: <sip: @ :5060> Fwd_inv F19 ACK sip: @ :9298;rinstance=aa040136f1a83a06 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1dd d5a5-13c c456-41f71b1e-4816c456 To: <sip: @samsung.com:5060>;tag=1e3cf677 Call-ID: 1e006c8-8442d5a5-13c c456-2b7f c456 CSeq: 1 ACK Via: SIP/2.0/UDP ;branch=z9hG4bk7fc6ab028c30a30ea83dec70e, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-4816c45e-98ef1264-4c05d5be Max-Forwards: 69 Contact: <sip: @ :5060> 64

65 3.5. Alphanumeric Username SIP UA may use alphabets as well as digits in its SIP-URI. In order to use alphanumeric username in SIP trunking mode, OfficeServ first has to register its alphanumeric username to a registrar. Once successfully registered, OfficeServ can send and receive SIP messages using the alphanumeric username contained in FROM/TO headers. From registrar s perspective, whichever is used for registration, there is no difference between handling an alphabetic username and handling a digit-only username Registering Alphanumeric Username MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com DNS SERVER1: USER NAME: sungwoo1769 AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE TRK REG EXP: RESP: ENABLE As shown above, username field in MMC837 is set to an alphanumeric value of sungwoo1769, and OfficeServ registers to a registrar as sungwoo1769. Figure 14. Register using Alphanumeric Username 65

66 Alpha_reg F1 REGISTER sip:samsung.com:5060 SIP/2.0 From: To: Call-ID: 1dc d5a5-13c bf8b1-5e78c88b-481bf8b1 CSeq: 1 REGISTER Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481bf8b3-ad437d9a Max-Forwards: 70 Supported: 100rel,replaces Expires: 1800 Contact: <sip:sungwoo1769@ :5060> Alpha_reg F2 SIP/ Proxy Authentication Required To: <sip:[email protected]:5060> From: <sip:[email protected]:5060>;tag=1da d5a5-13c bf8b3-303fd0b7-481bf8b3 Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf8b3-ad437d9a CSeq: 1 REGISTER Call-ID: 1dc d5a5-13c bf8b1-5e78c88b-481bf8b1 Proxy-Authenticate: Digest realm=" ",qop="auth",algorithm="md5",nonce=" c6f14bd7b7943cd86f1e5 da7" Alpha_reg F3 REGISTER sip:samsung.com:5060 SIP/2.0 From: <sip:[email protected]:5060>;tag=1da d5a5-13c bf8b3-303fd0b7-481bf8b3 To: <sip:[email protected]:5060> Call-ID: 1dc d5a5-13c bf8b1-5e78c88b-481bf8b1 CSeq: 2 REGISTER Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481bf8b3-ad437dd6-2475c752 Max-Forwards: 70 Supported: 100rel,replaces Expires: 1800 Proxy-Authorization: Digest username=" ",realm=" ",nonce=" c6f14bd7b7943cd86f1e5da7 ",uri="sip:samsung.com:5060",response="8f a33cd6c782b386b7c606",algorithm=md5,cnonce="ad437dd6",qop=auth,nc= \r Contact: <sip:sungwoo1769@ :5060> 66

67 Alpha_reg F4 SIP/ OK To: From: Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf8b3-ad437dd6-2475c752 CSeq: 2 REGISTER Call-ID: 1dc d5a5-13c bf8b1-5e78c88b-481bf8b1 Contact: <sip:sungwoo1769@ :5060>;expires= Outgoing Alphanumeric Username When sending out an INVITE message to alphanumeric destination, we have to consider following two points; How to call alphanumeric destination from legacy station in OfficeServ system? How to match a specific station with a registered alphanumeric username? DID and DOD numbers can be set using MMC323 Send CLIP table and MMC714 DID Digit table. (If not familiar with how to use these table, please refer to Basic Call MMC Settings.) When using digit-only caller and called number, there will be no problem. If OfficeServ has to use alphanumeric values, however, for the caller and called info, we need some intermediary storage to convert alphanumeric values into generic digit-only values. MMC839 contains mapping information which is used to convert digit number to alphanumeric called username. As we cannot dial alphanumeric called name from a legacy station in OfficeServ we dial this intermediary digit instead, and let OfficeServ convert the digit into a designated alphanumeric called name. MMC839 SIP USER SP1-001 USERNAME: AUTH UID: AUTH PWD: TEL NO: OPP0001 SITE URL: miyoung4692 TEL NO: 4692 CLI NAME: sungwoo1769 In above example, OfficeServ will convert a station-dialed digit 4692 (TEL NO) to designated called name of miyoung4692 (SITE URL), which is finally put into To Header. CLI NAME field specifies the value which should be put into FROM header. Note that value in CLI NAME field should be the same value that is registered to registrar. 67

68 Figure 15. Basic Outbound Call using Alphanumeric Username 68

69 Alpha_Outbound F1 INVITE SIP/2.0 From: 14e8e4d4-481bf69f To: Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f CSeq: 1 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481bf69f-ad3b5fe8-4dbd4596 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip:201@ :5060> Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Alpha_Outbound F2 SIP/ Proxy Authentication Required To: <sip:[email protected]:5060> From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b5fe8-4dbd4596 CSeq: 1 INVITE Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Proxy-Authenticate: Digest realm=" ",qop="auth",algorithm="md5",nonce="50f4a b5da191d a" Alpha_Outbound F3 ACK sip:[email protected]:5060 SIP/2.0 From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f To: <sip:[email protected]:5060> Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f CSeq: 1 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481bf69f-ad3b5fe8-4dbd4596 Max-Forwards: 70 Contact: <sip:201@ :5060> 69

70 Alpha_Outbound F4 INVITE SIP/2.0 From: 14e8e4d4-481bf69f To: Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481bf69f-ad3b601a-7dd4161c Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip:201@ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="50f4a b5da191d a ",uri="sip:[email protected]:5060",response="cbe5b4057c50a1a7afdfed1b779a9207 ",algorithm=md5,cnonce="ad3b601a",qop=auth,n Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Alpha_Outbound F5 SIP/ Trying To: <sip:[email protected]:5060> From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a- 7dd4161c CSeq: 2 INVITE Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Server: ININ-samsung-k1o0rnf

71 Alpha_Outbound F6 INVITE SIP/2.0 From: 14e8e4d4-481bf69f To: Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f CSeq: 2 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bk abba9703b6b6b4448, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a-7dd4161c Max-Forwards: 69 Supported: 100rel, replaces Contact: <sip:201@ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="50f4a b5da191d a ",uri="sip:[email protected]:5060",response="cbe5b4057c50a1a7afdfed1b779a9207 ",algorithm=md5,cnonce="ad3b601a",qop=auth,n Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Alpha_Outbound F7 SIP/ Trying Via: SIP/2.0/UDP ;branch=z9hG4bk abba9703b6b6b4448, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a-7dd4161c From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f To: <sip:[email protected]:5060> Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Date: Tue, 06 May :57:48 GMT CSeq: 2 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip:miyoung4692@ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE 71

72 Alpha_Outbound F8 SIP/ Ringing Via: SIP/2.0/UDP ;branch=z9hG4bk abba9703b6b6b4448, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a-7dd4161c From: 14e8e4d4-481bf69f To: Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Date: Tue, 06 May :57:49 GMT CSeq: 2 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip:miyoung4692@ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Alpha_Outbound F9 SIP/ Ringing Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a- 7dd4161c From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f To: <sip:[email protected]:5060>;tag=00141ca537d ec0e9b-76545d39 Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Date: Tue, 06 May :57:49 GMT CSeq: 2 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip:miyoung4692@ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE 72

73 Alpha_Outbound F10 SIP/ OK Via: SIP/2.0/UDP ;branch=z9hG4bk abba9703b6b6b4448, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a-7dd4161c From: 14e8e4d4-481bf69f To: Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Date: Tue, 06 May :58:03 GMT CSeq: 2 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip:miyoung4692@ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 206 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv Alpha_Outbound F11 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf69f-ad3b601a- 7dd4161c From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f To: <sip:[email protected]:5060>;tag=00141ca537d ec0e9b-76545d39 Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f Date: Tue, 06 May :58:03 GMT CSeq: 2 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip:miyoung4692@ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 206 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv 73

74 Alpha_Outbound F12 ACK SIP/2.0 From: 14e8e4d4-481bf69f To: Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f CSeq: 2 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481bf6ad-ad3b94f4-56dc0270 Max-Forwards: 70 Contact: <sip:201@ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="50f4a b5da191d a ",uri="sip:[email protected]:5060",response="cbe5b4057c50a1a7afdfed1b779a9207 ",algorithm=md5,cnonce="ad3b601a",qop=auth,n Alpha_Outbound F13 ACK sip:miyoung4692@ :5060 SIP/2.0 From: <sip:[email protected]:5060>;tag=1daa d5a5-13c bf69f- 14e8e4d4-481bf69f To: <sip:[email protected]:5060>;tag=00141ca537d ec0e9b-76545d39 Call-ID: 1dad d5a5-13c bf69f-2664efd6-481bf69f CSeq: 2 ACK Via: SIP/2.0/UDP ;branch=z9hG4bkf826b940a89e2bf9c9ccb63b8, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481bf6ad-ad3b94f4-56dc0270 Max-Forwards: 69 Contact: <sip:201@ :5060> Proxy-Authorization: Digest username=" ",realm=" ",nonce="50f4a b5da191d a ",uri="sip:[email protected]:5060",response="cbe5b4057c50a1a7afdfed1b779a9207 ",algorithm=md5,cnonce="ad3b601a",qop=auth,n Incoming Alphanumeric Username As mentioned before, receiving an INVITE message which contains digit-only called number in its To Header and mapping it to digit-only station number can be done by setting MMC714 table alone. When OfficeServ, however, is receiving an INVITE message which contains alphanumeric called number, it has to have additional table which maps the alphanumeric value to digit-only station number in order to decide which station to receive the call because generic MMC714 table only accepts digit value. As in the case of outgoing alphanumeric username, OfficeServ has this alphanumeric-to-digit conversion mechanism in MMC839 table. MMC839 SIP USER SP1-001 USERNAME: sungwoo1769 AUTH UID: AUTH PWD: TEL NO: 201 OPP0001 SITE URL: miyoung4692 TEL NO: 4692 CLI NAME: sungwoo

75 In above example, OfficeServ converts the alphanumeric value (sungwoo1769) in USERNAME field into digit value (201) specified in TEL NO field. The TEL NO value can be some other value which is different from actual station number because this number will be mapped to a value in generic MMC714 DID table, which originally has a role of mapping the called number to station number. To eliminate confusion, however, I recommend using station number directly in MMC839 and set the same value in MMC714 DID table as well. Following is the MMC714 table setting example. (Set by Default) MMC714 DID DIGIT DID DIGIT (001) DGT: 2** 1: B 2: B As we can see in the example, the alphanumeric value (sungwoo1769) is converted into a digit number (201) in MMC839 and the digit value is mapped to station DID number in MMC714. Figure 16. Basic Inbound Call using Alphanumeric Username 75

76 Alpha_Inbound F1 INVITE SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK4cca955e From: "miyoung4692" To: Call-ID: Max-Forwards: 70 Date: Tue, 06 May :31:12 GMT CSeq: 101 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Expires: 180 Accept: application/sdp Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 277 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv Alpha_ Inbound F2 SIP/ Proxy Authentication Required To: <sip:[email protected]> From: "miyoung4692" <sip:[email protected]>;tag=00141ca537d419223d1941c5-446f68e0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK4cca955e CSeq: 101 INVITE Call-ID: 00141ca5-37d4001c-4e49091c b0@ Proxy-Authenticate: Digest realm=" ",qop="auth",algorithm="md5",nonce="f4dbd55bb4c39efaca9a82f27e5d c61f" Alpha_ Inbound F3 76

77 ACK SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK4cca955e From: "miyoung4692" To: Call-ID: Date: Tue, 06 May :31:12 GMT CSeq: 101 ACK Alpha_Inbound F4 INVITE SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 From: "miyoung4692" To: Call-ID: Max-Forwards: 70 Date: Tue, 06 May :31:12 GMT CSeq: 102 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Proxy-Authorization: Digest e="20b39d6bd8d06efb2e7000c21a1dd36d",nonce="f4dbd55bb4c39efaca9a82f27e5dc61f",cn once="7f9905e7",qop="auth",nc= ,algori Expires: 180 Accept: application/sdp Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 277 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv 77

78 Alpha_ Inbound F5 SIP/ Trying To: From: "miyoung4692" Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 CSeq: 102 INVITE Call-ID: Server: ININ-samsung-k1o0rnf Alpha_Inbound F6 INVITE SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bkdd303660bac68ac5b4ab29589, SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 From: "miyoung4692" To: Call-ID: Max-Forwards: 69 Date: Tue, 06 May :31:12 GMT CSeq: 102 INVITE User-Agent: Cisco-CP7960G/8.0 Contact: Proxy-Authorization: Digest e="20b39d6bd8d06efb2e7000c21a1dd36d",nonce="f4dbd55bb4c39efaca9a82f27e5dc61f",cn once="7f9905e7",qop="auth",nc= ,algori Expires: 180 Accept: application/sdp Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 277 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:18 G729/8000 a=fmtp:18 annexb=no a=fmtp: a=sendrecv 78

79 Alpha_ Inbound F7 SIP/ Trying From: To: Call-ID: CSeq: 102 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bkdd303660bac68ac5b4ab29589 Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 Supported: 100rel,replaces Contact: Alpha_ Inbound F8 SIP/ Ringing From: To: 481cb53f Call-ID: CSeq: 102 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bkdd303660bac68ac5b4ab29589 Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 Supported: 100rel,replaces Contact: Alpha_ Inbound F9 SIP/ Ringing From: "miyoung4692" To: 481cb53f Call-ID: CSeq: 102 INVITE Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 Supported: 100rel, replaces Contact: 79

80 Alpha_Inbound F10 SIP/ OK From: To: 481cb53f Call-ID: CSeq: 102 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bkdd303660bac68ac5b4ab29589 Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 Supported: 100rel,replaces Contact: Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv Alpha_Inbound F11 SIP/ OK From: "miyoung4692" <sip:[email protected]>;tag=00141ca537d419223d1941c5-446f68e0 To: <sip:[email protected]>;tag=1da5a d5a5-13c cb53f-61851fc- 481cb53f Call-ID: 00141ca5-37d4001c-4e49091c b0@ CSeq: 102 INVITE Via: SIP/2.0/UDP :5060;branch=z9hG4bK70bea949 Supported: 100rel, replaces Contact: <sip:sungwoo1769@ :5060> Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv 80

81 Alpha_ Inbound F9 ACK SIP/2.0 Via: SIP/2.0/UDP :5060;branch=z9hG4bK186572f3 From: "miyoung4692" To: 481cb53f Call-ID: Max-Forwards: 70 Date: Tue, 06 May :31:15 GMT CSeq: 102 ACK User-Agent: Cisco-CP7960G/8.0 Proxy-Authorization: Digest e="20b39d6bd8d06efb2e7000c21a1dd36d",nonce="f4dbd55bb4c39efaca9a82f27e5dc61f",cn once="7f9905e7",qop="auth",nc= ,algori Alpha_ Inbound F9 ACK SIP/2.0 Via: SIP/2.0/UDP ;branch=z9hG4bkd070bf63bde8d9a295b33b3c2, SIP/2.0/UDP :5060;branch=z9hG4bK186572f3 From: "miyoung4692" To: 481cb53f Call-ID: Max-Forwards: 69 Date: Tue, 06 May :31:15 GMT CSeq: 102 ACK User-Agent: Cisco-CP7960G/8.0 Proxy-Authorization: Digest e="20b39d6bd8d06efb2e7000c21a1dd36d",nonce="f4dbd55bb4c39efaca9a82f27e5dc61f",cn once="7f9905e7",qop="auth",nc= ,algori 81

82 Multiple Alphanumeric Usernames Previous sections so far has described how to set OfficeServ s MMC databases in order to support an alphanumeric username. Then, it is high time to talk about how to make OfficeServ support multiple alphanumeric usernames. Actually I could have started explaining this from the beginning of alphanumeric username section because in real life OfficeServ is likely to have to support multiple alphanumeric usernames than to support a single alphanumeric username. But, if there were not for preliminary explanation made in previous chapters, readers of this document would be baffled or annoyed finding themselves still trying to understand what on earth is going on. I hope you have read thoroughly the sections from to and be ready to keep going. If not clearly understood yet, please go get some nice coffee and take a break, then go through the previous sections again. I know it may not be easy to understand the OfficeServ s internal mechanism of supporting alphanumeric username, especially for those who are not familiar with SIP and OfficeServ s MMC settings because even I and my officemate Ms. Jinsoo Eo, who programmed this part, sometimes forget how to setup alphanumeric support. If understood previous sections, it is relatively easy to set multiple alphanumeric usernames in MMC database. Let s assume that OfficeServ has been assigned one primary alphanumeric username (sungwoo1769) and one secondary alphanumeric username (tigerwoods). In this scenario, a registrar server requires authentication credential based on the primary alphanumeric username for both primary and secondary usernames. And OfficeServ system has two legacy stations (201 and 202) whose number will be mapped to each of the alphanumeric SIP username. Following shows how to setup MMC databases. MMC839 SIP USER SP1-001 USERNAME: sungwoo1769 AUTH UID: AUTH PWD: TEL NO: 201 SP1-002 USERNAME: tigerwoods AUTH UID: AUTH PWD: TEL NO: 202 OPP0001 SITE URL: miyoung4692 TEL NO: 4692 CLI NAME: sungwoo1769 SP-1 means Service Provider #1 and currently OfficeServ supports only one SIP Carrier at a time, therefore it should always be SP-1. From whichever station we make an outbound call dialing 4692, OfficeServ will put miyoung4692 in To Header and sungwoo1769 in From Header of the outgoing INVITE message. As to call receiving case, OfficeServ first checks value in To Header of a incoming INVITE message and converts the alphanumeric value to a digit value specified in TEL NO field, which finally decides a station to receive the call. 82

83 3.6. SIP Trunking Related MMC837 Options This section describes miscellaneous MMC837 database options which are related to SIP trunking message formats or call flows. As different SIP servers in different SIP carriers may require each different message specification or call flows, OfficeServ operator should adjust following MMC837 options in accordance with the server s request Proxy Name field Values in this field will override the URL part in FROM and TO header of OfficeServ s SIP messages. If some SIP carrier may want to receive SIP messages whose TO and FROM headers contain a value that is different from its outbound server domain name. In this case, we need to put the designated value into this PROXY NAME field. Unless designated, its value will remain as NULL and a value specified in OUT PROXY field will be used. MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com PROXY NAME: sec.samsung.com DNS SERVER1: USER NAME: sungwoo1769 AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE TRK REG EXP: Note that changing a value in PROXY NAME field simply changes the URL part of SIP messages and does not affect the messages outbound address nor DNS query result for outbound server. When PROXY NAME is set to sec.samsung.com INVITE sip:[email protected]:5060 SIP/2.0 From: <sip:[email protected]:5060>;tag=1da1f d5a5-13c e0956-7c9fbda1-481e0956 To: <sip:[email protected]:5060> Call-ID: 1da7dc0-8442d5a5-13c e0956-3f15e5d3-481e0956 CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481e0956-b5547a48-294c66f5 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip:201@ :5060> When PROXY NAME is set to NULL INVITE sip:[email protected]:5060 SIP/2.0 From: <sip:[email protected]:5060>;tag=1da1f d5a5-13c e0956-7c9fbda1-481e0956 To: <sip:[email protected]:5060> Call-ID: 1da7dc0-8442d5a5-13c e0956-3f15e5d3-481e0956 CSeq: 2 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481e0956-b5547a48-294c66f5 Max-Forwards: 70 Supported: 100rel,replaces Contact: <sip:201@ :5060> 83

84 Session TMR If this SESSION TMR option is set to UPDATE or REINVITE, OfficeServ system puts a Session Expires header into its outbound INVITE messages. Session Timer is used to refresh an active SIP session by sending a SIP request message to the other peer. The SIP request messages can be either UPDATE or re-invite, and the request messages are sent at each time period whose interval is specified in SESSION EXP field. If the refresher never gets the answer (200 OK) for the refresh request, it sends a BYE message to disconnect the SIP session. For more detailed, please refer to RFC4028. Figure 17. Session Refreshed by OfficeServ In following example, as SESSION TMR is set to UPDATE and SESSION EXP is set to 90 (sec), OfficeServ system sends UPDATE message at every 45 seconds which is the half of the value in Session Expires header. 84

85 MMC837 SIP OPTIONS ISP1 SIP SERVER: ENABLE OUT PROXY: samsung.com DNS SERVER1: USER NAME: AUTH USER: AUTH PSWD: 1234 REG PER USR: DISABLE SESSION TMR: DUPATE SESSION EXP: TRK REG EXP: Session_exp F1 INVITE SIP/2.0 From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 CSeq: 1 INVITE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 Max-Forwards: 70 Supported: timer,100rel,replaces Contact: <sip: @ :5060> Session-Expires: 90;refresher=uac Min-SE: 45 Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Session_exp F2 SIP/ Trying To: <sip: @samsung.com:5060> From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 CSeq: 1 INVITE Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Server: ININ-samsung-k1o0rnf

86 Session_exp F3 INVITE SIP/2.0 From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 CSeq: 1 INVITE Via: SIP/2.0/UDP ;branch=z9hG4bke1adb56ad8083a9d7275eaf32, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 Max-Forwards: 69 Supported: timer, 100rel, replaces Contact: <sip: @ :5060> Session-Expires: 90;refresher=uac Min-SE: 45 Content-Length: 255 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:18 G729/8000 a=rtpmap:4 G723/8000 a=rtpmap:8 PCMA/8000 a=sendrecv Session_exp F4 SIP/ Trying Via: SIP/2.0/UDP ;branch=z9hG4bke1adb56ad8083a9d7275eaf32, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 To: <sip: @samsung.com:5060> Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :45:18 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE 86

87 Session_exp F5 SIP/ Ringing Via: SIP/2.0/UDP ;branch=z9hG4bke1adb56ad8083a9d7275eaf32, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :45:18 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Session_exp F6 SIP/ Ringing Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 To: <sip: @samsung.com:5060>;tag=00141ca537d41c0d7959f2e9-622db6fd Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :45:18 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE 87

88 Session_exp F7 SIP/ OK Via: SIP/2.0/UDP ;branch=z9hG4bke1adb56ad8083a9d7275eaf32, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :45:19 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Supported: replaces,join,norefersub Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv Session_exp F8 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a6-b7b32bb8-5fd6cf50 From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 To: <sip: @samsung.com:5060>;tag=00141ca537d41c0d7959f2e9-622db6fd Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :45:19 GMT CSeq: 1 INVITE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Supported: replaces, join, norefersub Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv 88

89 Session_exp F9 ACK SIP/2.0 From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 CSeq: 1 ACK Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481ea4a8-b7b332e8-112f2434 Max-Forwards: 70 Contact: <sip: @ :5060> Session_exp F10 ACK sip: @ :5060 SIP/2.0 From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 To: <sip: @samsung.com:5060>;tag=00141ca537d41c0d7959f2e9-622db6fd Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 CSeq: 1 ACK Via: SIP/2.0/UDP ;branch=z9hG4bk57281bfc7a05dfda822819e38, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4a8-b7b332e8-112f2434 Max-Forwards: 69 Contact: <sip: @ :5060> Session_exp F11 UPDATE sip: @ :5060;transport=udp SIP/2.0 From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 To: <sip: @samsung.com:5060>;tag=00141ca537d41c0d7959f2e9-622db6fd Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 CSeq: 2 UPDATE Via: SIP/2.0/UDP :5060;rport;branch=z9hG4bK-481ea4d5-b7b3e2d8-1a Max-Forwards: 70 Supported: timer,100rel,replaces Contact: <sip: @ :5060> Session-Expires: 1800;refresher=uac Min-SE: 100 Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv 89

90 Session_exp F12 UPDATE SIP/2.0 From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 CSeq: 2 UPDATE Via: SIP/2.0/UDP ;branch=z9hG4bk878219c19d30a08d79327a2e9, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4d5-b7b3e2d8-1a Max-Forwards: 69 Supported: timer, 100rel, replaces Contact: <sip: @ :5060> Session-Expires: 1800;refresher=uac Min-SE: 100 Content-Length: 205 o=samsung_sip_gateway IN IP s=sip_call c=in IP m=audio RTP/AVP a=rtpmap:8 PCMA/8000 a=sendrecv Session_exp F13 SIP/ OK Via: SIP/2.0/UDP ;branch=z9hG4bk878219c19d30a08d79327a2e9, SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4d5-b7b3e2d8-1a From: <sip: @samsung.com:5060>;tag=1d8d8e0-8442d5a5-13c ea4a6-1dd3f ea4a6 To: <sip: @samsung.com:5060>;tag=00141ca537d41c0d7959f2e9-622db6fd Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :46:05 GMT CSeq: 2 UPDATE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK,BYE,CANCEL,INVITE,NOTIFY,OPTIONS,REFER,REGISTER,UPDATE Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv 90

91 Session_exp F14 SIP/ OK Via: SIP/2.0/UDP :5060;rport=5060;branch=z9hG4bK-481ea4d5-b7b3e2d8-1a From: To: Call-ID: 1d931f8-8442d5a5-13c ea4a ea4a6 Date: Thu, 08 May :46:05 GMT CSeq: 2 UPDATE Server: Cisco-CP7960G/8.0 Contact: <sip: @ :5060;transport=udp> Allow: ACK, BYE, CANCEL, INVITE, NOTIFY, OPTIONS, REFER, REGISTER, UPDATE Content-Length: 207 Content-Disposition: session;handling=optional o=cisco-sipua IN IP s=sip Call m=audio RTP/AVP c=in IP a=rtpmap:8 PCMA/8000 a=fmtp: a=sendrecv 91

92 4. SIP Peering Services SIP peering is relatively simple compared to SIP trunking in that it does not have to concern about registration nor outbound SIP server s behavior. On the other hand, SIP peering s functionalities are more depending on SIP UAs that are being involved in a SIP session and thus it has relatively limited functionalities. Internet OfficeServ 1 OfficeServ 2 Figure 18. Overall Configuration for SIP Peering mode and SIP Station mode SIP peer in this context means SIP UA and SIP peering does not need any intermediary SIP server in between two SIP peers. In SIP peering, all the SIP messages are out-bounded toward each other, therefore understanding outbound address setting is essential Basic Call Setup As mentioned above, to make an outbound call, OfficeServ first needs to know where to send the INVITE message. Once destination is set, OfficeServ can send INVITE message and make a SIP session with the other peer. MMC832 and MMC833 table contains dialed number-outbound IP address mapping mechanism. Let s look at following MMC example. MMC832 VOIP OUT DGT (O:00) ACCESS DGT: 2 (target destination prefix number) INSERT DGT: DGT LENGTH: 1 IP TABLE: 0 IP START: 0 SERVER USE: NO URI TYPE: SIP 92

93 SERVER USE field is set to NO and this makes OfficeServ set outgoing INVITE message s outbound address to an IP address specified in MMC833 (IP TABLE:0 and IP START index: 0). Note that if the SERVER USE field is set and OfficeServ is legitimately registered to a registrar, it will set the outbound address to an address specified in MMC837 OUT PROXY. MMC833 VOIP IP ADDR TB (00) ENTRY (00): (target destination ip address) TB (00) ENTRY (01): TB (00) ENTRY (02):... TB (01) ENTRY (00): TB (01) ENTRY (01): MMC833 table contains IP address list which will be specified as an outbound IP address of outgoing message by MMC832 setting. In the above example, MMC832 specifies IP TABLE 0 and IP START 0 which is mapped to TB 0 and ENTRY 00 in MMC833 and finally designates an IP address as an outbound IP address. 93